Manufacture of paper-pulp.



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smnnr D. "WELLS, OF'IMADIS ON, WISCONSIN, DEDICATED, BY MESNE ASSIGNMENTS, TO THE GOVERNMENT OF THE UNITED STATES AND TO THE PEOPLE OF THE UNITED Patented June Til, 191$.

[Application filed April 30, 191$. Serial No. 281,735.

STATES.

MANUFACTURE OF PAPER-PULP.

1 269 3541) Specification of Letters JPatent.

I No Drawing.

(DEDICATED T0 THE IPUBLTG.)

To all whom it may concern:

Be it known that I, SIDNEY D. Wants, a citizen of the United State, residing at Madison, in the county of Dane and State of Wisconsin, (whose post-office address is R. F. D. No. 4, Madison, Wisconsin,) have alty thereon.

My invention relates to the manufacture of paper pulp by alkaline processes from wood and other materials of a fibrous nature whereby the yield and quality of pulp obtained is increased while the consumption of chemical and duration of cooking is decreased.

The object of the invention is to add water to the charge durin the cooking and thereby diminish the actlon of the cookin liquors on the cellulose while the action 0 the cooking liquors onthe incrusting matter remains the same.

In the practice of the invention, the process is carried out in the following manner: The material. of a fibrous nature is pre ared by any of the means now practised in t e art and charged into the digester as in common practice. The cooking liquor is also added and any preliminary operations such as steaming, distillation of volatile oils, preliminary penetration, and the like, may be followed as desired. Steam is then admitted to the digester and the contents are brought up to the desired cooking pressure.

When the temperature in the digester is suflicient to cause the cooking liquor actively to attack the incrusting material, water is admitted into the digester in addition to the moisture carried in b t e steam, in suficient quantity, where y the action of the cooking liquors on the cellulose is diminished while the action of the cookin liquors on the incrusting matter remains e same.

The addition of water in this manner operates to increase not only the yield but also the quality of the pulp produced. The cook is carried out by any of the means commonly practised in the art. T have found that in cooking poplar by the soda process, the yield of pulp obtained was increased 9 per cent. by adding moisture with the steam so that the total moisture added amounted to 1500 gallons of water per cord of wood. Any increase'over this does not materially increase the yield.

The increase in yield found obtainable with the introduction of moisture is not obtainable by adding moisture at the beginning of the cook by means of using more dilute cooking liquors.

The addition of the moisture may be secured elther by admitting water withthe steam, by the use of wet steam, or by adding water into the digester through a separate inlet.

Having thus described my invention, T claim:

1. A process of cooking wood or other fibrous material for the production of paper pulp in which the desired amount of moisture is introduced to the digester during the cook in direct combination with the steam whereby the cellulose is protected to a marked degree from the actlon of the cookmg liquors while their action on theincrusting matter is in no way diminished.

2. A process of cooking wood or other fibrous material for the production of paper pulp in which the desired amount of moisture is introduced into the digester during the cooking by using wet steam carrying the desired amount of moisture in excess of that in saturated steam, whereby the cellulose is protected to a marked degree from the action of the cookin liquors while their action on the incrustlng matter is in no way diminished.

3. A process of cooking wood or other fibrous material for the production of paper pulp in which the desired amount of moisture over that admitted in the steam is introduced into the digester during the cook by a separate inlet whereby the cellulose is protected to a marked degree from the ac- Q moasso tion of the cooking liquors while their action on the incrustlng matter is in no way diminished.

4. A process of cooking wood or other 5 fibrous material for the production of paper pulp in which the desired amount of moisture is introduced into the digester during the cook by any means whatever, whereby A the cellulose is protected to a marked deee from the action of the cooking liquors while 10 their action on the incrusting matter is in no we diminished.

n testimony, I aflix my signature in the presence of two subscribin witnesses.

- SIDNE D. WELLS. Witnesses:

OTTO Knnss, G. C. MCNA'UGHTON. 

